New engines for BMW Z4
Two new twin-turbo, four-cylinder 2.0-litre engines replace the current six-cylinder unit ini the sDrive23i and sDrive30i.
The new engines appear in the sDrive20i and the sDrive28i versions. The cars will be more powerful and 20% more efficient than the previous models, says BMW.
A six-speed manual gearbox comes as standard, although an eight-speed automatic is an option.
Prices for the new versions have yet to be announced.